Crossing-gate



C. H. TILLETT AND T. A. ALLAN.

CROSSING GATE.

APPLICATION FILED III/III. 5, |920.

Patented July 12, 1921.

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C. H. TILLETT AND T. A. ALLAN.

CROSSING GATE.

APPLICATION FILED MAR. 1920. 1,384,544, Patented July 12, 1921.

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/m/e/#ars e UNITED STATES CHARLES H. TILLETT AND THOMAS ALLAN,

PATENT OFFICE.

OF MONTREAL, QUEBEC, CANADA.

CROSSING-GATE. i

To all whom t may concern v Be it known that we, CHARLES H. TILLETT, acitizen of the United States of America, and THOMAS A. ALLAN, a subjectof the King of Great Britain, both residents ofthe city of Montreal, inthe Province vof Quebec and Dominion of Canada, have invented certainnew and useful Improvements in Crossing-Gates, of which the following isa full, clear, andexact description. g

This invention relates to improvements in l crossing gates andparticularly to gates 0perated by electricmotors. The object of thevinvention is to provide means whereby the motor is allowed to attainits speed under no load conditions before movement ofthe gate commences.

A further object is to provide means permitting the motora certain freerun after thel gate movement' has ceased in order that the motor maycome to a stop naturally and without the use of a brake.

A still further object is yto provide means whereby the gate is moved ata variable rate of speed. the maximum speed being at an intermediatepoint of the travel without 1 variation in thespeed of the motor.Various other objects and advantages will be ascertained from thefollowing specification.

The device consistsbriefly of a housing to which the gate ispivotallyconnected, the said housing containingk a motordriven screw operating anut into and out of engagement with a lever connected to the gate.Stopping and starting switches for the motor are provided in positiontobe operated by the nut.v g v In the ydrawings vention Figure 1 is aplan view of the device showing the casing open.

Fig. 2 is a section on the line 2 2, Fig. 1. Fig. 3 is asection on theline 33, Fig. 2. Fig. 4 is a plan view of one of the motor whichillustrate the incontrol switches.

Fi 5 is a side elevation of one of the switc es.

Fig. 6 is'an end elevation, partly in section, of one of the switches.`

Referring more particularly to the draw,`

-nected by Specification of Letters Patent. Patented July 12, 1921.Application filed March 5, 1920. Serial No. 363,465.

ings, 11 designates a casing or pedestal of `any suitable construction,upon which a vguide 15 arranged in parallelism with the worm, Vthe wormand 'guide being at right angles to the shaft 13 and a suitable'distance therefrom. A motor 16 is provided preferably within the casingand is operably congears 17 with the worm 14. A nut 18 is provided onthe'worm and is disposed ini slidable engagement with the guide 15,whereby the nut is held against revolution with the worm so that uponrevolution of the worm the nut moves longitudinally thereof.

A lever or arm 19 is rigidly connected to the shaft 13 carrying thegate, the longitudinal axis of said lever being preferably at an angleof about 4.50 to the longitudinal axis of the gate. The free end of thelever is bifurcatedprovidinga longitudinally dis posed slot 20. Adjacentedges of the bifurcations or aws 21 are iared as shown at 22. Theseflared edges are formed preferably at angles of about 4.50 to thelongitudinal axis of the lever, whereby when the leveris at aninclination of 4:5 one of said flared edges will be horizontal and theother will be vertical, asshown in Fig. 2. A stud 23, which may` ifdesired, be provided with an antifriction' roller or sleeve, is mountedon the nut 18 axially parallel with the shaft 13 and in position toengage the horizontally ared edge 22 when the lever is in its extremeinclined position. The nut is additionally provided with bosses or thelike 24C and 25 for roperating the motor controlling switches 26,

` lines Fig. 2.

Each of the blades 33 is provided with a tip 36 hingedlyv mounted to thebody of .the blade by a pin 37 and normally held in ahnement by aspring-pressed finger' 3S carried by the body of the blade. These bladeextensions 36 rest normally between the spring lingers 39 of theterminals 31, 32 and are held .in this position by spring-pressed,pivoted latches el() forming part of the terminals B1, 32. The switch isnormally held in closed circuit position by a spring al tensionedbetween the cross-arm Eel and a post 42.

The operation of the mechanism of the gate proper is extremely simple.The mtor being started in the proper direction the screw is revolved anddrives the nut toward the opposite end of the casing. It will be clearlyseen in Fig. 2 that the stud 23 rests under the horizontally flared edge22 so that the nut will have considerable movement before the studstrikes the vertical edge or the inclined edge of the slot 20. In thisway the motor is allowed to work up to speed under no load conditions.As soon as the stud 23 engages in the slot proper it commences to movethe lever 19 with it, so that the gate which is rigidly connected withthe lever is also moved. As movement increases and the gate rises, thelever swings down toward a veitical position, thus bringing` the pointof contactwith the stud 23 closer to the shaft 13. The result is, thatwith the reduced length of lever a given movement of the nut producesgreater angular movement of the lever, so that the gate is moved morerapidly as the lever assumes a vertical position. In the same way thespeed of the gate is decreased after the lever passes a verticalposition and swings up to the inclined position shown in dotted lVhenthe lever reaches this inclined position the stud leaves the slot 2()and travels under the horizontal flared edge 22, so that it produces nomovement of the lever or gate. As the lever comes to rest in its dottedposition it operatively engages the switch 26 and opens the motorcircuit at exactly the moment that the stud 23 leaves the slot 20. Inthis way the driving power of the motor is applied to the gate until itsmovement is complete and then the motor is disconnected from the gate sothat it is under no load and simultaneously deprived of power. Beingunder no load the motor runs of its own momentum at gradually decreasingspeed and finally stops naturally and without the application of brakesafter having carried the stud from the mouth of the latch 20 to theextremity of the flared edge. This movement of the stud during thestopping of the motor permits an equal and opposite Vmovement'of thestud when the motor is coming up to speed for the next operation of thegate. It will be noted that the stud docs not disengage the flared edges22 at the ends of its travel but remains as a stop holding the lever andgate against movement from their intended positions. This is clearlyshown in Fig. 2, the lever is shown in full lines being in properrelation to the gate. (.lbviously, any attempt to lift the gate isresisted by the downward pressure oi' the lever on the stud 23.

The operation of the switches 26 and 27 by the nut is as follows z--Bothswitches are normally in the position shown in Figs. a,

and 6, maintaining two circuits closed between the motor and acontroller (not shown), these circuits being arranged for operating themotor in positive and reverse directions. As the nut approaches itsposition shown in dotted lines, Figs. 1 and 2, the boss 2t thereofengages the roller bearing lever and tilts the same against the 'tensionof the spring 41, so that the blades 33 swing upwardly and tend to drawtheir extensions 36 from between the contacts or spring fingers 39.lVithdrawal of the blade extensions 36 is, however, momentarilyprevented by the latches 40, with the result that the blade extensionsswing on their pivots 37 and assume an angular relation with respect tothe blade bodies 33. The tails of these extensions thus lift thespringpressed plates 3S. The arcuate movement of the pivot pins 37 andof the extensions themselves eventually withdraws the extensions 36 fromthe latches 40, and the springpressed plates 38 become operative towithdraw the extensions from between the contacts 39 and swing theextensions into alinement `with the blades 33. In this way the circuitis broken very quickly and burning of the parts SP and avoided. When themotor is to be again started the controller oiiierated to open thecircuit through the open switch 26 and establish the circuit through theclosed switch 27. As the nut withdraws from the switch 26 the boss 24releases the lever and the spring 41 closes the switch. As there is nocurrent flow through this switch owing to the setting of the controllerthe slow closing of the'switch as the nut leaves it will not have anydetrimental effect. The spring 41 draws the blade extensions 36 down andpast the latches which are thrust back as the parts 36 pass and thenreturned to latching position Vover the parts 36 by their springs.ll'lhen the nut resumes its position as shown in full lines the boss 25strikes the lever 35 of the switch 27 which operates in exactly the samenanner as the switch 26.

From the foregoing description it will be evident that the apparatuscomprises a few simple parts not liable to get out of order. The motoris protected and complication of starting resistance .avoided byallowing ythe motor to come Iup'tospeedfunder no load. Similarly theucomplication 'of .brakes and means for stopping the nut exactly atspecilied pointsfis entirely overcomeby permitting it a free run underno load after the power is ycut o1f,.so that it 'stops naturally by lossof momentumJv The gate is locked in either of its positions against anyunauthorized return to its former position and the locking is effectedwithout the addition of a single part. The gate is not only operated ata speed gradually increasing from he start to a medio point and thendecreaspable of relative movement in the line of nut travel only at thecommencement and completion of the motor operation, so as'to give ireerun to the motor at such times.

2. In a device of the character described, the combination with a memberto be operated and a driving motor, of an operating connection includinga traveling member operatively connected to the motor so as to travelcontinuously during motor operation,

said traveling member being arranged toV move freely for a substantialdistance out of engagement with said member at the commencement andcompletion of its travel and in driving relation with said first memberduring the intermediate portion of its travel.

3. In a device of the character described, the combination with a gateand an operating motor therefor, of a connection between the motor andthe gate including a lever carried by the latter, and a travelingmotoroperated nut adapted to move in driving engagement with said leverduring the intermediate portion of its travel and to have `Free movementat the commencement and completion of its travel so as to afford freerun to the motor at said times.

4. In a device of the class described, the combination with a gate andan operating motor therefor, of a screw connected to said motor forrevolution, an irrevolubly held nut on said screw, and a slotted leverrigidly connected with the gate and receiving said nut in the slot totransmit power from the motor to the gate.

5. A device according to claim 4, in which the lever slot is formed topermit of nut movement at the ends of lever travel without disconnectionof the nut and lever.

`6. A device according to claim 4, in which thelever is arranged'tooperate through an angle of approximately 900 from a position inclinedapproximately 45", the edges of the lever` defining the outer endof theslot being arranged at an angle of approximately 900 and occupyinghorizontal .and vertical planes at the extremities of lever movement.

7. A device according' to claim 4, in which the lever edges defining theslot at the extremity of the lever are flared, the angle between saidedges and the angle through the lever movement being together equal tosubstantially 180".

8. A device according to claim 4, in which the lever edges deiining theouter end of the slot are flared, whereby at one extremity of levermovement one edge Vof the slot is in parallelism with the direction ofnut movement and at the other extremity of lever movement the other'edgeis in parallelism with the direction of nut movement.

9. A device according to claim 4, in which the lever is so disposed thatits point of contact with the nut approaches and then recedes from thecenter of lever oscillation.

l0. In a device of the class described, the combination with a gate andan operating motor therefor, of mechanical power transmitting connectionbetween the gate and motor, a pair of circuits adapted to energize saidmotor for operation in either direction and a normally closed switch ineach of said circuits including a pair of blades, an insulated operatinglever projecting into the path of the connection, extensions pivotallyconnected to said blades and spring actuated to normally maintainalinement with the blades, contacts located for engagement-with saidblade extensions, and spring actuated latches normally holding the bladeextensions in engagement with said contacts and operative to move theextensions out of alinement with the blades during opening of theswitch, whereby said extensions will be sharply withdrawn from thecontacts by their alining springs on the disengagement of the extensionsand latches, and a spring adapted to return the blade extensions intoengagement with the contacts upon disengagement of the actuating leverand mechanical connection. f

l1. In a. device of the class described, the combination with a gate`and an operating motor therefor, of mechanical power transmittingconnection between the gate and circuit maker and engageeble by themement of said holding means, and a spring chanical connection to openthe switch, and arranged to close the switch upon disen- 10 meansreleasably engaging said circuit gagement of the switch and mechanicalconmaker und holding the seme in closed switch necton.

position during part of the movement of In Witness whereof, wc havehereunto set said operating lever, whereby Said circuit our hands.

maker is flexed to cause by its resiliency a .i CHARLES H. TILLETT.rs1-pid opening of the switch upon disengage- THOMAS A. ALLAN.

